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          <h1 class="post-title" itemprop="name headline">数组</h1>
        

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        <p>数组 ：动态数组，栈，队列<br><a id="more"></a><br>在内存中，数组是一块连续的区域。 拿上面的看电影来说，这几个人在电影院必须坐在一起。<br>数组需要预留空间，在使用前要先申请占内存的大小，可能会浪费内存空间。 比如看电影时，为了保证10个人能坐在一起，必须提前订好10个连续的位置。这样的好处就是能保证10个人可以在一起。但是这样的缺点是，如果来的人不够10个，那么剩下的位置就浪费了。如果临时有多来了个人，那么10个就不够用了，这时可能需要将第11个位置上的人挪走，或者是他们11个人重新去找一个11连坐的位置，效率都很低。如果没有找到符合要求的作为，那么就没法坐了。<br>插入数据和删除数据效率低，插入数据时，这个位置后面的数据在内存中都要向后移。删除数据时，这个数据后面的数据都要往前移动。 比如原来去了5个人，然后后来又去了一个人要坐在第三个位置上，那么第三个到第五个都要往后移动一个位子，将第三个位置留给新来的人。 当这个人走了的时候，因为他们要连在一起的，所以他后面几个人要往前移动一个位置，把这个空位补上。<br>随机读取效率很高。因为数组是连续的，知道每一个数据的内存地址，可以直接找到给地址的数据。<br>并且不利于扩展，数组定义的空间不够时要重新定义数组。<br><a href="https://blog.csdn.net/qq_25806863/article/details/70607204" target="_blank" rel="noopener">数组和链表的区别</a> </p>
<h1 id="动态数组"><a href="#动态数组" class="headerlink" title="动态数组"></a>动态数组</h1><p>java中的ArrayList<br>按照需要对数组进行扩容或者缩容<br>实际上是重新创建一个新的数组，把原有数组复制过去<br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br><span class="line">90</span><br><span class="line">91</span><br><span class="line">92</span><br><span class="line">93</span><br><span class="line">94</span><br><span class="line">95</span><br><span class="line">96</span><br><span class="line">97</span><br><span class="line">98</span><br><span class="line">99</span><br><span class="line">100</span><br><span class="line">101</span><br><span class="line">102</span><br><span class="line">103</span><br><span class="line">104</span><br><span class="line">105</span><br><span class="line">106</span><br><span class="line">107</span><br><span class="line">108</span><br><span class="line">109</span><br><span class="line">110</span><br><span class="line">111</span><br><span class="line">112</span><br><span class="line">113</span><br><span class="line">114</span><br><span class="line">115</span><br><span class="line">116</span><br><span class="line">117</span><br><span class="line">118</span><br><span class="line">119</span><br><span class="line">120</span><br><span class="line">121</span><br><span class="line">122</span><br><span class="line">123</span><br><span class="line">124</span><br><span class="line">125</span><br><span class="line">126</span><br><span class="line">127</span><br><span class="line">128</span><br><span class="line">129</span><br><span class="line">130</span><br><span class="line">131</span><br><span class="line">132</span><br><span class="line">133</span><br><span class="line">134</span><br><span class="line">135</span><br><span class="line">136</span><br><span class="line">137</span><br><span class="line">138</span><br><span class="line">139</span><br><span class="line">140</span><br><span class="line">141</span><br><span class="line">142</span><br><span class="line">143</span><br></pre></td><td class="code"><pre><span class="line">/**</span><br><span class="line"> * @author :xie</span><br><span class="line"> * Email: 1487471733@qq.com</span><br><span class="line"> * Date: 2018/12/4</span><br><span class="line"> * Time: 14:41</span><br><span class="line"> * Describe:动态数组，自动变化长度</span><br><span class="line"> */</span><br><span class="line">public class Array&lt;E&gt; &#123;</span><br><span class="line">    private E[] data;</span><br><span class="line">    private int size;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 传入长度的构造函数</span><br><span class="line">     * @param capacity</span><br><span class="line">     */</span><br><span class="line">    public Array(int capacity)&#123;</span><br><span class="line">        data= (E[]) new Object[capacity];</span><br><span class="line">        size=0;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 默认构造函数，默认长度为10</span><br><span class="line">     */</span><br><span class="line">    public Array()&#123;</span><br><span class="line">        this(10);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 获取数组中元素的个数</span><br><span class="line">     * @return</span><br><span class="line">     */</span><br><span class="line">    public int getSize()&#123;</span><br><span class="line">        return size;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 获取数组的长度</span><br><span class="line">     * @return</span><br><span class="line">     */</span><br><span class="line">    public int getLength()&#123;</span><br><span class="line">        return data.length;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 数组是否为空，即size是否为0</span><br><span class="line">     * @return</span><br><span class="line">     */</span><br><span class="line">    public boolean isEmpty()&#123;</span><br><span class="line">        return size==0;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 在指定位置插入一个元素</span><br><span class="line">     * @param index</span><br><span class="line">     * @param e</span><br><span class="line">     */</span><br><span class="line">    public void  add(int index,E e)&#123;</span><br><span class="line">        if(index &lt; 0 || index &gt; size)&#123;</span><br><span class="line">            throw new IllegalArgumentException(&quot;Add failed. Require index &gt;= 0 and index &lt;= size.&quot;);</span><br><span class="line">        &#125;</span><br><span class="line">        if(size == data.length)&#123;</span><br><span class="line">            resize(2 * data.length);</span><br><span class="line">        &#125;</span><br><span class="line">        //因为数组的特性，向指定位置插入一个元素，需要把这个位置后面的元素整体向后移动一个位置</span><br><span class="line">        //如果直接赋值，会覆盖掉原index位置的数据，导致数据丢失</span><br><span class="line">        for(int i = size - 1; i &gt;= index ; i --)&#123;</span><br><span class="line">            data[i + 1] = data[i];</span><br><span class="line">        &#125;</span><br><span class="line">        data[index] = e;</span><br><span class="line">        size++;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 向数组的size位置添加一个元素</span><br><span class="line">     * @param e</span><br><span class="line">     */</span><br><span class="line">    public void  add(E e)&#123;</span><br><span class="line">        int index=size;</span><br><span class="line">        add(index,e);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 获取指定位置的数据</span><br><span class="line">     * @param index</span><br><span class="line">     * @return</span><br><span class="line">     */</span><br><span class="line">    public E get(int index)&#123;</span><br><span class="line">        if(index &lt; 0 || index &gt;= size)&#123;</span><br><span class="line">            throw new IllegalArgumentException(&quot;get failed. Require index &gt;= 0 and index &lt;= size.&quot;);</span><br><span class="line">        &#125;</span><br><span class="line">        return data[index];</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 更新指定位置的数据</span><br><span class="line">     * @param index</span><br><span class="line">     * @param e</span><br><span class="line">     */</span><br><span class="line">    public void set (int index,E e)&#123;</span><br><span class="line">        if(index &lt; 0 || index &gt;= size)&#123;</span><br><span class="line">            throw new IllegalArgumentException(&quot;get failed. Require index &gt;= 0 and index &lt;= size.&quot;);</span><br><span class="line">        &#125;</span><br><span class="line">        data[index]=e;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 删除指定位置的元素</span><br><span class="line">     * @param index</span><br><span class="line">     */</span><br><span class="line">    public  E remove(int index)&#123;</span><br><span class="line">        if(index &lt; 0 || index &gt;= size)&#123;</span><br><span class="line">            throw new IllegalArgumentException(&quot;Remove failed. Index is illegal.&quot;);</span><br><span class="line">        &#125;</span><br><span class="line">        E ret = data[index];</span><br><span class="line">        for(int i = index + 1 ; i &lt; size ; i ++)&#123;</span><br><span class="line">            data[i - 1] = data[i];</span><br><span class="line">        &#125;</span><br><span class="line">        size --;</span><br><span class="line">        // loitering objects != memory leak</span><br><span class="line">        data[size] = null;</span><br><span class="line"></span><br><span class="line">        if(size == data.length / 4)</span><br><span class="line">        &#123;</span><br><span class="line">            resize(data.length / 2);</span><br><span class="line">        &#125;</span><br><span class="line">        return  ret;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 将数组空间的容量变成newCapacity大小</span><br><span class="line">     * @param newCapacity</span><br><span class="line">     */</span><br><span class="line">    private void resize(int newCapacity)&#123;</span><br><span class="line">        E[] newData = (E[])new Object[newCapacity];</span><br><span class="line">        for(int i = 0 ; i &lt; size ; i ++)&#123;</span><br><span class="line">            newData[i] = data[i];</span><br><span class="line">        &#125;</span><br><span class="line">        data = newData;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure></p>
<h1 id="栈"><a href="#栈" class="headerlink" title="栈"></a>栈</h1><p>基于动态数组完成，先进后出<br>添加元素时，data[size]=e<br>删除元素时，remove(size-1)<br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br></pre></td><td class="code"><pre><span class="line">public class ArrayStack&lt;E&gt; implements Stack&lt;E&gt; &#123;</span><br><span class="line"></span><br><span class="line">    private Array&lt;E&gt; data;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 带参数的构造函数</span><br><span class="line">     * @param capacity</span><br><span class="line">     */</span><br><span class="line">    public ArrayStack(int capacity)&#123;</span><br><span class="line">        data=new Array&lt;&gt;(capacity);</span><br><span class="line">    &#125;</span><br><span class="line">    public ArrayStack()&#123;</span><br><span class="line">        data=new Array&lt;&gt;();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public int getSize() &#123;</span><br><span class="line">        return data.getSize();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public boolean isEmpty() &#123;</span><br><span class="line">        return data.isEmpty();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public void push(E e) &#123;</span><br><span class="line">        data.add(e);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public E pop() &#123;</span><br><span class="line">        return data.remove(data.getSize()-1);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public E peek() &#123;</span><br><span class="line">        return data.get(data.getSize()-1);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure></p>
<h1 id="队列"><a href="#队列" class="headerlink" title="队列"></a>队列</h1><p>先进先出<br>分为基本队列和循环队列<br>基本队列依靠动态数组完成<br>循环队列需要单独实现</p>
<h2 id="基本队列"><a href="#基本队列" class="headerlink" title="基本队列"></a>基本队列</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br></pre></td><td class="code"><pre><span class="line">public class ArrayQueue&lt;E&gt; implements Queue&lt;E&gt; &#123;</span><br><span class="line"></span><br><span class="line">    private Array&lt;E&gt; array;</span><br><span class="line"></span><br><span class="line">    public ArrayQueue(int capacity)&#123;</span><br><span class="line">        array = new Array&lt;&gt;(capacity);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    public ArrayQueue()&#123;</span><br><span class="line">        array = new Array&lt;&gt;();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public int getSize() &#123;</span><br><span class="line">        return array.getSize();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public boolean isEmpty() &#123;</span><br><span class="line">        return array.isEmpty();</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public void enqueue(E e) &#123;</span><br><span class="line">        array.add(e);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public E dequeue() &#123;</span><br><span class="line">        return array.remove(0);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public E getFront() &#123;</span><br><span class="line">        return array.get(0);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<h2 id="循环队列"><a href="#循环队列" class="headerlink" title="循环队列"></a>循环队列</h2><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br><span class="line">90</span><br><span class="line">91</span><br><span class="line">92</span><br><span class="line">93</span><br><span class="line">94</span><br><span class="line">95</span><br><span class="line">96</span><br></pre></td><td class="code"><pre><span class="line">/**</span><br><span class="line"> * @author :xie</span><br><span class="line"> * Email: 1487471733@qq.com</span><br><span class="line"> * Date: 2018/12/6</span><br><span class="line"> * Time: 13:45</span><br><span class="line"> * Describe: 循环队列</span><br><span class="line"> * 给队首和队尾打标，当front==tail（即front和tail同时指向一个位置时，表示数组为空）</span><br><span class="line"> * 循环队列需要浪费一个位置来标识队满的情况。当tail+1==front时，表示队满</span><br><span class="line"> */</span><br><span class="line">public class LoopQueue&lt;E&gt; implements Queue&lt;E&gt; &#123;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 数据</span><br><span class="line">     */</span><br><span class="line">    private E[] data;</span><br><span class="line">    /**</span><br><span class="line">     * front 队首；tail 队尾</span><br><span class="line">     */</span><br><span class="line">    private int front, tail;</span><br><span class="line">    /**</span><br><span class="line">     *</span><br><span class="line">     */</span><br><span class="line">    private int size;</span><br><span class="line"></span><br><span class="line">    public LoopQueue()&#123;</span><br><span class="line">        this(10);</span><br><span class="line">    &#125;</span><br><span class="line">    public LoopQueue(int capacity)&#123;</span><br><span class="line">        data = (E[])new Object[capacity + 1];</span><br><span class="line">        front = 0;</span><br><span class="line">        tail = 0;</span><br><span class="line">        size = 0;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public int getSize() &#123;</span><br><span class="line">        return size;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public boolean isEmpty() &#123;</span><br><span class="line">        return size==0;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 推数据入栈，首先判断是否队满，如果队满，重新构建一个数组</span><br><span class="line">     * 然后把数据添加给队尾</span><br><span class="line">     * @param e</span><br><span class="line">     */</span><br><span class="line">    @Override</span><br><span class="line">    public void enqueue(E e) &#123;</span><br><span class="line">            if ((tail+1)%data.length==front)&#123;</span><br><span class="line">                resize(getCapacity()*2);</span><br><span class="line">            &#125;</span><br><span class="line">        data[tail] = e;</span><br><span class="line">        tail = (tail + 1) % data.length;</span><br><span class="line">        size ++;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    /**</span><br><span class="line">     * 删除队首元素，然后把front指向下一个元素</span><br><span class="line">     * @return</span><br><span class="line">     */</span><br><span class="line">    @Override</span><br><span class="line">    public E dequeue() &#123;</span><br><span class="line">        if(isEmpty())&#123;</span><br><span class="line">            throw new IllegalArgumentException(&quot;Cannot dequeue from an empty queue.&quot;);</span><br><span class="line">        &#125;</span><br><span class="line">        E ret = data[front];</span><br><span class="line">        data[front] = null;</span><br><span class="line">        front = (front + 1) % data.length;</span><br><span class="line">        size --;</span><br><span class="line">        if(size == getCapacity() / 4 &amp;&amp; getCapacity() / 2 != 0)</span><br><span class="line">            resize(getCapacity() / 2);</span><br><span class="line">        return ret;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    @Override</span><br><span class="line">    public E getFront() &#123;</span><br><span class="line">        return null;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    private void resize(int newCapacity)&#123;</span><br><span class="line"></span><br><span class="line">        E[] newData = (E[])new Object[newCapacity + 1];</span><br><span class="line">        for(int i = 0 ; i &lt; size ; i ++)</span><br><span class="line">            newData[i] = data[(i + front) % data.length];</span><br><span class="line"></span><br><span class="line">        data = newData;</span><br><span class="line">        front = 0;</span><br><span class="line">        tail = size;</span><br><span class="line">    &#125;</span><br><span class="line">    public int getCapacity()&#123;</span><br><span class="line">        return data.length - 1;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

      
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              <div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-1"><a class="nav-link" href="#动态数组"><span class="nav-number">1.</span> <span class="nav-text">动态数组</span></a></li><li class="nav-item nav-level-1"><a class="nav-link" href="#栈"><span class="nav-number">2.</span> <span class="nav-text">栈</span></a></li><li class="nav-item nav-level-1"><a class="nav-link" href="#队列"><span class="nav-number">3.</span> <span class="nav-text">队列</span></a><ol class="nav-child"><li class="nav-item nav-level-2"><a class="nav-link" href="#基本队列"><span class="nav-number">3.1.</span> <span class="nav-text">基本队列</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#循环队列"><span class="nav-number">3.2.</span> <span class="nav-text">循环队列</span></a></li></ol></li></ol></div>
            

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